1. Field of the Invention
The present invention relates to alkoxysilane-functional urethane compositions and in particular to alkoxysilane-functional urethane compositions useful in adhesive, sealant and coating compositions.
2. Background Art
Adhesives are commonly used to join or fasten two or more adherends. Adherends are considered as being any two or more materials, or pieces of material that are being joined together, including wood, metals, plastics, paper, ceramics, stone, glass, concrete, etc. Adhesives used for these purposes are based on a wide range of technologies, including elastomer/solvent/resin mixtures, epoxies, latexes, polyurethanes, silicones, cyanoacrylates, acrylics, hot melts, and others. Such adhesives can have one or more drawback, such as they may contain solvents which are toxic and often flammable, they can be incompatible with one or more classes of adherends, they can have undesirably long cure times and in many cases the bonds they form of are of insufficient strength.
It is often desirable for coatings applied to substrates to provide a desirable appearance, in many cases by applying multiple coating layers, the last of which can be a pigmented or unpigmented topcoat. Unfortunately, as the article containing the coated substrate ages, scratches that occur through normal “wear and tear”, tend to deteriorate the appearance of the coated surface of the substrate,
A sealant is typically a thin film, often containing a plastic, that is applied onto one or more surfaces on one or more substrates to prevent passage of a liquid or gas through the film. The sealant can be used to prevent exposure of the substrate or is often additionally used to prevent exposure via defects in a substrate or between gaps that can exist between substrates.
U.S. Pat. No. 6,590,028 to Probst, et al. discloses an aqueous two-component polyurethane systems, a process for their production, and their use for the production of coatings having increased impact strength, high stability properties and outstanding optical properties.
U.S. Published Patent Application 2003/0039846 A1 to Roesler et al. discloses a two-component coating compositions containing a polyisocyanate component, an isocyanate-reactive component that contains less than 3% by weight of an aromatic polyamine and 0.1 to 1.8 wt. %, based on the weight of the other components of a compound containing at least one epoxy group and at least one alkoxysilane group.
U.S. Published Patent Application 2003/0173026 A1 to Wu et al. discloses silane functional adhesive compositions for bonding a window to a painted substrate. The process includes applying to the glass or the substrate the silane functional adhesive composition; contacting the glass with the substrate; and allowing the adhesive to cure.
U.S. Published Patent Application 2003/0153671 A1 to Kaszubski et al. discloses a moisture curable adhesive that includes a polymer containing reactive silicon end groups; a clear filler; and a dehydrating agent.
However, both initially and especially after exposure to the elements, heretofore known adhesive, sealant and coating compositions do not provide sufficient tensile strength and/or elongation to break properties to protect substrates onto which they have been applied. As a result, cured films derived from such adhesive, sealant and coating compositions are prone to crack, blister and or chip, leaving the underlying substrate exposed.
Therefore, there is an established need in the art for adhesive, sealant and coating compositions that provide coating films with excellent tensile strength and elongation to break properties both initially and after exposure to the elements.